/Pro·te·us/ (pro´te-us) a genus of gram-negative, motile bacteria usually found in fecal and other putrefying matter, including P. morga´nii, found in the intestines and associated with summer diarrhea of infants, and P. vulga´ris, often found as a secondary invader in various localized suppurative pathologic processes; it is a cause of cystitis.http://medical-dictionary.thefreedictionary.com/PROTEUS

Proteus, can cause urinary tract infections and hospital-acquired infections. P.mirabilis, a cause of wound andurinary tract infections. most strains of P. mirabilis are sensitive to ampicillin and cephalosporins. P. vulgaris is notsensitive to these antibiotics.